Tube expander



Feb. 27, 41951 F.` P. FITZGERALD ET AL TUBE EXPANDER mm Y mm No mi l ii.

Filed Aug, J 1945 Patented Feb. 27, 1951 UNITED STATES PATENT OFFICE TUBE EXANDER Application August 1, 1945, Serial No. 608,337

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) 3 Claims.

The present invention concerns a tube expander and particularly concerns a rotary tool to expand the ends of boiler or condenser tubes into watertight and mechanically interlocked relation with their supportingheaders.

In the manufacture of boilers, condensers or similar devices wherein a plurality of parallel tubes are mounted at their ends in supporting headers so that uid of one type can circulate Within the tubes While fluid of another` type can circulate outside of the tubes, it is necessary that the tubes be mounted in their supporting headers in such manner that a rigid mechanical interu lock is effected and also that a watertight seal be provided so that fluid cannot escape through the headers past the ends of the tubes. Itis customary in the manufacture of such devices to provide headers with slightly oversize openings into which the extremities of the tubes are loosely inserted, and the extremities of the tubes are then expanded into contact with the oversize openings to effect a tight mechanical interlock Vand a watertight seal.

The present invention provides for performing the expanding operation a rotary tool that incorporates safety features for preventing injury to the operator and automatic self-adjustment features for preventing damage to the tool or work and for providing maximum speed and efficiency of operation. In its preferred form, the tool comprises a tapered spindle, a cylindrical cage adapted for reciprocation upon the spindle, and a plurality of needle rollers loosely supported in the cage periphery in such manner that upon reciprocation of the cage, the rollers are cammed I7 radially by the action of the tapered spindle. Resilient means are provided for constantly urging the cage toward the small end of the spindle in which position the rollers are in their retracted or radially withdrawn position. The tool is further provided With a shank to permit mounting in a rotary tool holder, for example, in a compressed-air-operated tool holder of conventional design.

In operation, the tool is inserted cage i'lrst into the extremity of a tube to be expanded and the tapered shank is forced through the cage to cam the needle rollers radially outward to expand the tube. The resilient means for constantly urging the cage toward the narrow end of the spindle automatically conditions the tool for operation at al1 times and insures that the needle rollers are in their retracted position during initial insertion into the extremity of the tube.

An object of this invention is to provide an 65 2 expanding tool that eliminates any need for manual adjustment during operation or for manual adjustment preparatory to starting an expanding operation and provides for completely automatic self-adjustment.

Another object of the invention is to provide an expanding tool that eliminates danger of in- J'ury to the operators hand by eliminating the need for manual adjustment.

Another object of the inventionvis to provide an expanding tool having a self-adjusting reciprocating cage whereby breakage of the tool due to inadvertent misadjustment is eliminated.

Another object is to provide an expanding tool having a reciprocating cage which is constantly urged by resilient means into proper operating position.

Another object of the invention is to provide an expanding tool that automatically adjusts itself at the initiation of each expanding operation whereby the tool can be used for insertion into and expansion of boiler tubes that are relatively inaccessible and where a single hand alone can be used for operating the tool due to inaccessibility.

Further objects and advantages of this invention, as well as its construction, arrangement and operation, are apparent from the following description and claims in connection with the accompanying drawings, in which,

Fig. l is an elevational View of a preferred embodiment of the invention at the start of an expanding operation. l

Fig. 2 is a sectional view of the tool shown in Fig. 1 as it appears upon the completion of an expanding operation.

Fig. 3 is a transverse sectional View taken substantially along the lines 3-3 of Fig. 1.

Fig. 4 is a transverse sectional View taken substantially along the line 4 4 of Fig. 2.

A preferred form of the invention comprises a tapered spindle II upon which is disposed for longitudinal reciprocation a cage I2. Mounted loosely within cage I2 are a series of three circumferentially-spaced needle rollers I3, so disposed that upon longitudinal reciprocation of cage I2, rollers I3 are cammed radially under the influence of tapered spindle II. Thus, with cage i2 disposed at the narrow end of spindle II as shown in. Fig. 1, rollers I3 are retracted radially inwardly within cage I2, while if cage I2 is reciprocated to the wide end of spindle II as shown in Fig. 2, rollers I3 are cammed radially outward with respect to cage I2. Mounted for rotation upon cage I2 is a slip ring I4 which is 3 secured against movement to the right as seen in Fig. 1 by a nut I5 threaded on cage I2 as shown at II and secured in position by a set screw I'I. Nut I5 is so adjusted that slip ring I4 can rotate freely.

The narrow extremity of spindle II is provided with a threaded portion I8 .upon which is mounted a stop nut I9 that serves to limit movement of cage I2 toward the narrow end of spindle II. The opposite end of spindle II is provided with a retainer disc which serves -to limit movement of cage I2 in the direction of the wide end of spindle II. Mounted for free rotation upon spindle II adjacent nut I5 is a Disposed between bushing 2i and retainer disc 2e is a conical-spiral compression spring 22 that constantly urges cage I2 toward the narrow end of spindle ,I I. Cage SI2, however, can be reciprocated toward the wide end of spindle II into the position shown in Fig. 2 against vthe action-cf Vspring 22 and in such vpositionspring 22 is compressed into a plane as shown `in Fig. 2o. Extending from retaining disc Z in :alignment -with spindle '.II is a tapered vshank 23 of conventional design to provide for mounting kthe tool in a holder of conventional -design (not shown) such as a compressed-air-driven rotary tool holder.

In Fig. 1 is disclosed a boiler tube 24 and a header 25 having an oversize opening 26. Openi-ng 26 is provided with a groove 21. Cage I2 is shown at the beginning of its penetration .into

the extremity of tube 24 and before any expanding action has taken place. In Fig. 2, 4cage -I2 is shown completely penetra-ted into the :end of tube 24 with slip ring I4 contacting lthe end of tube 24 to retain cage I2 in proper position ,for the expanding operation. Spindle IrI is reciprocated through cage I2 with rollers I3 cammed radially outward to expand tube 224 and force a portion of the periphery thereof `into groove-2l as shown at 28 whereby a tight ime- .chanical interlock and watertight seal between tube 24 and header 25 are provided.

Operation of the device is as follows. With the extremity of boiler tube 24 mounted loosely in oversize header opening 26 and with shank 23 .of .the expanding tool mounted Iin a suitable rotary tool holder', the expanding operation is :effected in the following manner. cage I2 vat the start of the operation is positioned against stop nut I9 at the narrow end of spindle II under the iniiuence of spring 22 and `needle `vrollers :I3 are in radially withdrawn position. :Shank 23 and spindle II are then aligned with the opening in tube 24 and cage VI2 is inserted .into -the end of -tube 24 until slip 'ring 'I4 abuts the end of Vtube 2li. During this operation, spindle II and cage I2 are rotating under the influence of the tool holder (not shown).V Spindle II isnow urged toward the left as lshown :in the @drawings lagainst the action of .spring 2,2 `which 'operation causes rollers I3 to be cammed outwardly under the influence of tapered spindle TII.

- Rollers I3 are forced Ainto contact with .the inner 'surface of tube 24 and, .as they are cammed further outwardly, they force tube 24 to expand V-andforce a portion of the exterior Aof tube 24 into groove 2 formed in header 25 as :shown at 28. The operation can be stopped Aat lany desired point when inthe operators judgment rollers I3 have caused suiicient expansion .of tube v24. In any event, the operation is `brought to a conclusion automatically when spring 22 becomes completely compressed so that :spindle Il As shown vin Fig. .1, Y

.4 cannot be reciprocated further. Thus rollers I3 have an automatically-defined maximum radius of expansion to prevent injury to the tool or to tube 24.

Spring 22 constantly urges cage I2 toward the narrow end of spindle I I and thus provides automatic self-adjustment `of the tool and eliminates any need for manual adjustment. For example, at the start of an expanding operation, spring 22 automatically forces cage I2 against stop I9 at the narrow end of spindle I I. Under such conditions, rollers I3 are in their position of maximum radial retraction whereby the tool is conditioned for insertion into a tube and for initiation of an expanding operation. Thus it is impossible that the cage be inadvertently positioned at the wide part of the spindle with the rollers in radially expanded position, whereby damage might result at the start of the expanding operation and it is further not necessary that the operator manually -position the cage. Thus the tool and work are protected from damage through possible misadjustment of the tool, and the operator Vis protected from injury to his hand since manual adjustment of `the tool is not necessary.

Modications and changes Vcan be madein the Vabove embodiment of this invention without departing from the spirit and scope thereof as set forth in the appended claims.

The invention described herein may be Vmanufactured and used `loy or for the Government of the United States of America for governmental purposes without the payment of vany royalties thereon or therefor.

What is claimed is:

l. A :tool comprising -a tapered spindle, a cage with rollers adapted for radial movement ulOOn sliding of the cage along the spindle, means `at the narrow end of the spindle for limiting movement of the cage, a relatively thin, disc-shaped retainer of relatively large diameter, a 'conica-lspiral compression spring having the end Yof larger diameter seated on one face .of said retainer, `and a relatively thin bushing of smaller diameter than said retainer'and seated vagainst the end of smaller diameter of .said spring, said retainer and said bushing being arranged in alignment with the axis of vsaid conical-spiral spring, said retainer, bushing and spring being adapted to vbe disposedabout and in coaxial relation with the tapered portion of the spindle, v*sa-id spring being arranged for compression yalong its axis into a flat spiral so .that said retainer and .bushing are lbrought into relatively -close proximity and said retainer, spring .and bushing form a compact unit having -a .relatively small dimension `in a radially linward direction upon relative movement of `the. cage toward the narrow portion vof .said spindle, a .stop .at the narrow end of said .spindle to :limit relative movement .of saidcage toward said narrow portion, a vrelatively thin, disc-shaped retainer .of relatively `large diameter disposed upon the `enlarged portion of said tapered spindle, a conical-spiral vcompression spring Vhavi ing the end of larger diameter seated on a face of said retainer, said spring being disposed about said spindle and extending toward the narrow portion of said spindle, and a relatively thin bushing seated at the other extremity of said spring for sliding movement on said vspindle and adapted to bear against said cage, said bushing being of smaller diameter than said` retainer, said retainer serving to limit relative `movement of said cage and bushing toward the enlarged prtion of said spindle, said spring serving to urge said cage and bushing into relative position toward the narrow end of the spindle whereby said rollers can move inwardly, said spring being arranged for compression along its axis into a at spiral so that said retainer and bushing are brought into relatively close proximity and said retainer, spring and bushing form a compact unit having a relatively small dimension'along said axis.

3. In a portable and hand-operated tube expander a tapered spindle, a cage with rollers adapted for radial movement upon'sliding of the cage along the spindle, and means at the narrow end of the spindle for limiting movement of the cage toward the narrow end, a relatively thin disc-shaped retainer of relatively large diameter, said retainer being adapted to be disposed upon the enlarged end of the spindle, a conical-spiral compression spring having the end ofA larger diameter seated on one face of said retainer and extending toward the narrow end of said spindle,

REFERENCES CITED The following references are of record in the le of this patent: l

UNITED STATES PATENTS Number Name Date 648,765 Lykken et al May 1, 1900 1,015,447 Lillibridge Jan. 23, 1912 1,077,837 Kerrigan Nov. 4, 1913 1,138,311 Pollard May 4, 1915 1,265,283 Wiedelge May 7, 1918 1,322,921 Maupin Nov. 25, 1919 1,357,059 Ihsen Oct. 26, 1920 1,417,979 Dixon May 30, 1922 1,819,915 Morrison Aug. 18, 1931 1,921,810 Duchesne Aug. 8, 1933 1,942,612 Naher Jan. 9, 1934 

